Epigenetics can be defined as the study of interactions between genome and environment that leads to changes in gene expression without changing the DNA sequence. The study of epigenetics therefore leads to an understanding of genome function and consequences of aberrant environmental stimuli. In recent years, epigenetics has revealed some of the most extraordinary forms of gene regulation and quickly become one of the most exciting research areas in genetics, genomics, and developmental biology. Even as genome projects are providing the complete nucleotide sequence of a myriad of organisms, researchers are turning to the field of epigenetics to understand how that sequence is interpreted in the context of the cell or the organism. epigenetic processes encompass an impressive diversity of mechanisms including noncoding RNA (ncRNA), DNA methylation, prions, histone modifications, chromatin remodeling, higher order chromosome structures, and nuclear compartments. The richness and versatility of these biological processes have been elucidated through the study of a wide range of diverse organisms. Our conference prides itself on inclusiveness, respect for the exchange of ideas, and value of learning from the full range of model systems, including prokaryotes, fungi, ciliates, plants, worms, insects, and mammals. Here, we submit our application seeking support for the 8th meeting of the Gordon Research Conference (GRC) on Epigenetics. Since its inception in 1995, this GRC has played a key role in moving forward the field of epigenetics, earning an international reputation for generating new research avenues and providing a unique setting for bringing together a diverse group of scientists. We aim to (1) Advance our understanding of epigenetic mechanisms by facilitating the exchange of information and ideas from experts working in a wide array of epigenetic systems;(2) Introduce new issues and new questions that push the boundaries of epigenetics, while at the same time, provide a venue in which alternative viewpoints can be heard and discussed openly;and (3) Promote the careers of young investigators, including students, postdoctoral fellows, and new principal investigators including underrepresented minorities. In additon to featuring the classic epigenetic phenomena such as imprinting, X-inactivation, RNAi, paramutation, and transvection, the 2009 conference will place special emphasis on genome-environment interactions as they relate to human health and disease. Several sessions will be devoted to understanding the role of environmental modulators such as diet, toxins, parental care, and endocrine disruptors in promoting normal development, behavior, cancer, diabetes, and aging. Towards improving knowledge of molecular mechanisms, the conference will feature international leaders studying the roles of higher order chromatin structure, noncoding RNA, repeat elements, nuclear organization, and morphogenic evolution. Examples will be drawn from model organisms in the prokaryotic, fungal, plant, and animal kingdoms. Public Health Relevance: Epigenetics can be defined as the study of interactions between genome and environment that leads to changes in gene expression without changing the DNA sequence. The study of epigenetics therefore leads to an understanding of genome function and consequences of aberrant environmental stimuli. In the 2009 Epigenetics GRC, special emphasis will be placed on two aspects of epigenetics - first, the role of novel molecular mechanisms that underlie epigenetic processes, and second, the role of environmental modulators such as diet, toxins, parental care, and endocrine disruptors in promoting normal development, behavior, cancer, diabetes, and aging.